﻿function showPages(name) { //初始化属性
    this.name = name;      //对象名称
    this.page = 1;         //当前页数
    this.pageCount = 1;    //总页数
    this.argName = 'page'; //参数名
    this.showTimes = 1;    //打印次数
}
showPages.prototype.getPage = function () { //丛url获得当前页数,如果变量重复只获取最后一个
    var args = location.search;
    var reg = new RegExp('[\?&]?' + this.argName + '=([^&]*)[&$]?', 'gi');
    var chk = args.match(reg);
    this.page = RegExp.$1;
}
showPages.prototype.checkPages = function () { //进行当前页数和总页数的验证
    if (isNaN(parseInt(this.page))) this.page = 1;
    if (isNaN(parseInt(this.pageCount))) this.pageCount = 1;
    if (this.page < 1) this.page = 1;
    if (this.pageCount < 1) this.pageCount = 1;
    if (this.page > this.pageCount) this.page = this.pageCount;
    this.page = parseInt(this.page);
    this.pageCount = parseInt(this.pageCount);
}
showPages.prototype.createHtml = function () { //生成html代码mode
    var strHtml = '', prevPage = this.page - 1, nextPage = this.page + 1;
    strHtml += '<span class="pages">第 ' + this.page + '页 /共 ' + this.pageCount + '页</span>';
    strHtml += '<span class="number">';
    if (prevPage < 1) {
        strHtml += '<a title="已经是第一页，请勿再点。。。" class="first">&#171;首页</a>';
        strHtml += '<a title="已经是第一页，请勿再点。。。" class="previouspostslink">&#139;</a>';
    } else {
        strHtml += '<span title="First Page"><a href="javascript:' + this.name + '.toPage(1);">&#171;首页</a></span>';
        strHtml += '<span title="Prev Page"><a href="javascript:' + this.name + '.toPage(' + prevPage + ');">&#139;</a></span>';
    }
    if (this.page != 1) strHtml += '<span title="page larger"><a class="first" href="javascript:' + this.name + '.toPage(1);">1</a></span>';
    if (this.page >= 5) strHtml += '<span class="extend">...</span>';
    if (this.pageCount > this.page + 2) {
        var endPage = this.page + 2;
    } else {
        var endPage = this.pageCount;
    }
    for (var i = this.page - 2; i <= endPage; i++) {
        if (i > 0) {
            if (i == this.page) {
                strHtml += '<span title="当前为第 ' + i + '页" class="current">' + i + '</span>';
            } else {
                if (i != 1 && i != this.pageCount) {
                    strHtml += '<span title="Page ' + i + '"><a href="javascript:' + this.name + '.toPage(' + i + ');">' + i + '</a></span>';
                }
            }
        }
    }
    if (this.page + 3 < this.pageCount) strHtml += '<span class="extend">...</span>';
    if (this.page != this.pageCount) strHtml += '<span title="Page ' + this.pageCount + '"><a href="javascript:' + this.name + '.toPage(' + this.pageCount + ');">' + this.pageCount + '</a></span>';
    if (nextPage > this.pageCount) {
        strHtml += '<a title="已经是最后一页，请勿再点。。。" class="nextpostslink">&#155;</a>';
        strHtml += '<a title="已经是最后一页，请勿再点。。。" class="nextpostslink" >&#187;末页</a>';
    } else {
        strHtml += '<a title="Next Page" class="nextpostslink" href="javascript:' + this.name + '.toPage(' + nextPage + ');">&#155;</a>';
        strHtml += '<a title="Last Page" class="last" href="javascript:' + this.name + '.toPage(' + this.pageCount + ');">&#187;末页</a>';
    }
    strHtml += '</span><br />';
    return strHtml;
}
showPages.prototype.createUrl = function (page) { //生成页面跳转url
    if (isNaN(parseInt(page))) page = 1;
    if (page < 1) page = 1;
    if (page > this.pageCount) page = this.pageCount;
    var url = location.protocol + '//' + location.host + location.pathname;
    var args = location.search;
    var reg = new RegExp('([\?&]?)' + this.argName + '=[^&]*[&$]?', 'gi');
    args = args.replace(reg, '$1');
    if (args == '' || args == null) {
        args += '?' + this.argName + '=' + page;
    } else if (args.substr(args.length - 1, 1) == '?' || args.substr(args.length - 1, 1) == '&') {
        args += this.argName + '=' + page;
    } else {
        args += '&' + this.argName + '=' + page;
    }
    return url + args;
}
showPages.prototype.toPage = function (page) { //页面跳转
    var turnTo = 1;
    if (typeof (page) == 'object') {
        turnTo = page.options[page.selectedIndex].value;
    } else {
        turnTo = page;
    }
    self.location.href = this.createUrl(turnTo);
}
showPages.prototype.printHtml = function (mode) { //显示html代码
    this.getPage();
    this.checkPages();
    this.showTimes += 1;
    document.write('<div id="pages_' + this.name + '_' + this.showTimes + '" class="pages"></div>');
    document.getElementById('pages_' + this.name + '_' + this.showTimes).innerHTML = this.createHtml(mode);

}
showPages.prototype.formatInputPage = function (e) { //限定输入页数格式
    var ie = navigator.appName == "Microsoft Internet Explorer" ? true : false;
    if (!ie) var key = e.which;
    else var key = event.keyCode;
    if (key == 8 || key == 46 || (key >= 48 && key <= 57)) return true;
    return false;
}